The order of a phase locked loop (PLL) circuit corresponds to the number of poles in the transfer function of the PLL, or the number of integrating elements in the PLL. A simple first order PLL includes a voltage controlled oscillator (VCO) as an integrating element. The VCO performs an integration of a control voltage supplied by a phase detector through a forward path, and provides an output signal to the phase detector through a feedback path. Second and higher order PLLs include a loop filter in addition to a VCO. In general, higher order PLLs are more stable, but more complex and slower, than lower order PLLs. Most PLLs use a third order architecture without a transconductor. Some fourth order PLLs use an open loop, source degenerated amplifier for the transconductor. Such fourth order PLLs have headroom issues for both the input and the output of the PLL. Additionally, the transconductance is highly dependent on the input device providing the input to the PLL.